Summary: Approaching ballistic transport in
suspended graphene
XU DU, IVAN SKACHKO, ANTHONY BARKER AND EVA Y. ANDREI*
Department of Physics and Astronomy, Rutgers the State University of New Jersey, 136 Frelinghuysen Rd, Piscataway, New Jersey 08854, USA
*e-mail: eandrei@physics.rutgers.edu
Published online: 20 July 2008; doi:10.1038/nnano.2008.199
The discovery of graphene1,2
raises the prospect of a new class of
nanoelectronic devices based on the extraordinary physical
properties3­6
of this one-atom-thick layer of carbon. Unlike
two-dimensional electron layers in semiconductors, where the
charge carriers become immobile at low densities, the carrier
mobility in graphene can remain high, even when their density
vanishes at the Dirac point. However, when the graphene
sample is supported on an insulating substrate, potential
fluctuations induce charge puddles that obscure the Dirac point
physics. Here we show that the fluctuations are significantly
reduced in suspended graphene samples and we report low-
temperature mobility approaching 200,000 cm2